Explosive mine



Aug. 28, 1928.

H. GRUBER EXPLOSIVE MINE Filed Nov. 14, 1 927 2 Sheets-Sheet 1 v ii. M//, w.

TM T ml 9% V N 5. I B

ATTORNEYS.

Aug. 28, 1928. 1,682,560

H. GRUBER EXPLOSIVE MINE med Nov. 14, 192'! I 2 Sheets-Sheet 2- Patented Au 28, 192 8.

UNITED STATES HANS GB'UBECR', OF MUHLIDORF, GERMANY.

EXPLOSIVE MINE.

- Application filed November 14, 1927, Serial No 233,025, and in. Germany May 18, 1925.

tant point and, in given cases, as a hand grenade.

The chief feature of the invention comj prises 'a novel firing device which is so constructed and arranged that it functions with absolute certainty and can never fail. -When the mine' is subjected to compression, as for example, when trodden on or when a vehicle. passes over it, a. pressure member tlflVGlSlng.

the mine transversely, for-example, axially, which is ordinarily held in position by a shearing pin, is pressed down so as to shear the pin and release a spring actuated striker previously retained by the pressure member,

the striker-being directed radially and, on

release, firing an explosive charge. The movement of the pressure member normally held by the shearing pin is in a transverse or axial direction, whilst the movement of the striker takes place at right angles thereto and in radial direction in a special igniter casing and is thus'quite independent-of the safety device formed by the shearing pin ot the transversely movable pressure member.

Since, moreover,- the thickness of the shearing pin can be calculated and selected to correspond to any desired pressure}. the firing device functions with absolute accuracy and failures are impossible.

The invention is illustrated in the accompauying drawings wherein Fig. 1 is a verticalsection through the mine. Fi t Fig.2 is an elevation of the pressure member. showing the means for retaining thestriking bolt. I

Fig. shows the shearing pin and a further safety device cooperating with the pressure member.

Fig. 4 is a vertical section of an alternative form of construction of the explosive mine.

' Fig. 5 is a horizontalsection of the mine shown in Fig. 4.

According to Fig. 1, the explosive charge I) is contained in the sheet metal casing a of the mine, which is shaped like a disk or converse lens. Two cushions 0 are interposed between the charge and the casing near the edge. The casing d of the firing chamber,

in which the striker f is adapted to move radially in the mine. In the centre of the mine the striker'casing is traversed by the cylindrical pressure member 9 which is guided axially. In the normal condition of the mine, the pressure member 9' is located with its upper end abutting againstthe to pressure sleeve h and its lower end is guide in the bottom pressure sleeve 71. In this position, the pressure member is firmly secured to the igniter 03 against downward movement by means of a shearin pin is of precisely under the action of the spring e,-is arranged selectable shearing strength, the igniter casing being seated firmly on the bottom pressure sleeve i. The cylindrical pressure member g has a recess in its periphery with a slotted cover, the slotl (Figs. 1 and 2) terminating atthe top in an enlargement m. A spring actuated striker f is provided with a neck which fits into the narrow part of the slot -Z and is prevented from moving out by. the head 1%. Thus the striker can only be released through the large-d portion m of the slot.

In the event of the mine being trodden on or a: wheel passing overit, the pressure exerted causes the shearing pin to be sheared,

so that the pressure member 9 can freely move downwards. The enlarged portion m of the slot then registers with the head n of the striker, so that the latter is released'and is propelled by the spring against the percussion cap 0 so as to fire the mine. The forward propulsion of the striker can take place perfectly freely, since this movement is in no wav impeded by the shearing pin is.

In order to protect the mine-from explo sion during transport or the like, a further safety device is provided which is represented 'the slot r. The upwardly projecting lugs 9 then register with the'slot s in the bottom of the pressure member 9 and no longer support the pressure member so that when the pressure on the mine exceeds the value necessary to shear the pin is, the mine can be exploded. The rotary movement of the rotary member is limited in its end position by a p nshaped projection t. The guide tube M, which is provided with openings mounted on the igniter casing d, projects at its outer end into a charging head '0 which is adapted to be closed by a screw stopper 'w. The charging head '0, after screwing out the stopper w, permits of the mine being primed. Furthermore on account of this arrangement, the

mine can also be used as a hand grenade by screwing in a hand grenade stem provided with percussion fuse or time fuse instead of the cover 10. Also the screw cover enables the mine to be employed as a remote control mine.

In the second form of construction shown in Figs. 4 and 5, a plurality of igniter casings (l with spring actuated strikers, in this case three, are provided, which are distributed in a radial arrangement. All the igniter casings d are radially directed towards the centre. On their outer ends are arranged the transversely movable pressure members 9, which are each held on to the igniter casing by means of a shearing pin is. The three pressure members g are uniformly distributed on a circle having its centre at the centre of the mine. \Vhen the mine is loaded, immaterially at what point, at least one of the 'three pressure members is actuated to release a striker and by this means the mine is caused to explode.

The ends of the radial igniter casings d directed towards the middle terminate. in a cylindrical easing 2, in which is rotatable a safety cylinder 4 provided with star-shaped passages 3. In the position visible from Fig. 5, all the igniter casings d are connected with one another by the star-shaped passages-3. Consequently the ignition from one igniter casing is propagated in all the others. If, however, the safety cylinder 4 is rotated, the inner ends of all the igniter casings are closed. Furthermore, a star-shaped plate 5 is secured on the rotatable safety cylinder 4 and rotates with it. The periphery of the plate 5 is provided with notches 6 which, in the position shown in Fig. 5, liberate the axial pressure members g, whilst on rotation of the safety cylinder 4, the periphery of the plate 5 engages in corresponding slots 7 of the pressure members 9 as can be seen from Fig. 4. By this means the pressure members are prevented from moving axially. In this position, therefore, thi'ee safety devices are provided in the mine, the shearing pins k, the starshaped plate 5 and the safety cylinder 4, so

that even" in the event of pressure on the 'mine, no axial movement of a pressure member 9 can take place nor can a stream of fire from a percussion cap 0 penetrate into the safety cylinder 4. The end positions of the plate 5 and thus also of the safety cylinder- 4 are determined by projections 17. The retation of the safety cylinder 4 is effected from mine consists of two dish-shaped parts a and a which are fitted together making a tight oint at the periphery. They are held together in the centre by a bolt 11 provided with a bayonet fastening as shown in Fig. 4. The transverse pressure members 9 rest with their lower ends on the flat base 12 of the lower dish. If now the mine when laid flat on the ground is trodden on or a wheel passes over it, the two plates, which are held apart from one another a certain distance across the middle, are pressed together at the point of pressure in the manner of a lever. By such a pressure, at least one of the ressure members g functions and the particu ar pin is sheared whereby the ignition is effected. The particular percussion ca 0 transmits a stream of fire through the saety cylinder from whence the fire spreads out in all directions.

Since nost explosives can only be fired by appropriate detonation, in the constructional form illustrated, four or more small tubes 13 prov ded with detonators 14 are arranged within the mine. Three of these detonators are arranged radially between the igniteis whilst one detonator 13 is arranged axially as shown in Fig. 4. These four detonators also tern'iinate at their inner ends in corresponding'passages of the safety cylinder 4. The stream of fire from one of the igniters engages the detonators 14 therefore so that at least one of the detonators will detonate andthe whole mine explode. As can be seen from Figs. 4 and 5, the detonators can be inserted in the mine from outside afterwards. Until this has been done even if it is made unsafe it will never detonate when .trodden on or passed over by a wheel.

A hinged handle 15 is mounted on the mine so that it can be readily transported.

In order to be able to use the mine also as a heiwy hand grenade or as aminecapable of being fired from a distant point, a stopper 1G is provided, as shown in Fig. 4, on which can be screwed a hand grenade stem with percussion or timefuse or-even a lengthof time fuse cord, a glow fuse and the like. Furthermore the mine can be employedin two' parts. The parts a and a, are readily separated by undoing the joint 11. In this case the disk 0. can be employed'as a mine adapted to explode when trodden on and the other disk a as a hand grenade or explosive mine. The plate a can either be laid with the pressure members 9 on the solid ground or the gaged, whilst in the first case the disk only needs to be loaded at any point in order to cause detonation. The other plate can be employed by itself alone as a hand grenade or mine operated from a distant point.

This possibility of using the mine in two parts is particularly valuable in a road blocking arrangement, since the mine hardly projects from the ground and by earth and the like can very easily be made incapable of recognition so that the mine field does not attract attention,

I claim 1. In an explosive mine, the combination of a disk-shaped casing, an explosive charge contained in said casing, an i'gniter tube arranged radially in said casing, a spring actuated striking bolt arranged in said igniter tube, a transversely arranged pressure operof a disk-shaped casmg, an explosive charge ated member for retaining said strikingbolt and a shearing pin for holding said pressure member below a predetermined prejsure.

2. In an explosive mine, the combmation of a disk-shaped casing, an explosive charge contained in said casing, an igniter tube arranged radiall in said casing, a spring actuated striking olt in said igniter tube, said igniter tube extending inwards beyond the centre of the caslng and being provided with a "transverse assa e a ressure member a rranged axially in said casing extending through the passage in-sa d igniter casing, a shearing pin extendmg through said pressure member and into the wall of said igniter casing and means whereby said pressure member holds said strlking bolt in one posltion and releases-said striking bolt in another position.

3. In an explosive mine, the combination or a disk-shaped casing, an explosive charge contained in said casing, an igniter tube arranged radially in said casing, a spring actuated striking bolt arranged in saidigniter tube, said igniter tube extending inwards beyond the centre and being provided with a transverse passage, a pressure member arranged axially in said casing extending through the passage in said igniter casing, a shearing pin extending through said pressure member and into the wall of said igniter casing, means whereby said pressure member holds said striking bolt in one position and releasessaid striking bolt in another position,

'a cap into which the top end of said cylindrical pressure member enters a sleeve for guiding the lower end of said cylindrical member and a rotary member adapted in one osition to hold the pressure member against ongitudinal movement in said sleeve and when rotated to another position to leave 4 space in said sleeve for longitudinal movement of the pressure member.

4. In an explosive mine, the combination of a disk-shaped casing, an explosive charge contained in said casing, an igniter tube arranged radially Within said casing and ex tending beyond the centre and having a transverse passage, a pressure member arranged axially in said casing and extending through said transverse passage, said pressure member bein reduced in its central part, a tubular mem'er covering said reduced part, said tubular member having a longitudlnal slot enlarged at one end, a spring pressed striking bolt in said igniter tube, said bolt having a to leave space for movement of said pressure member shearing said shearing pin and releasing said striking bolt to fire said mine.

5. In an explosive mine, the combination contained in said casing, an igniter tube arranged radially within said casing and extending beyond the 'centre and having a transverse pasage, a tubular extension on said igniter tube extending towards the periphery of said casing, said casing having an openmg in its periphery at the end of said tube, and a removable stopper for said opening,

a pressure member arranged axially in said casing and extending through said tran: verse passage, sald pressure member being reduced in its central part, a tubular member covering said reduced part, said tubular member having a longitudinal slot enlarged at one end, a spring pressed striking bolt in said igniter. tube, said boltjhaving a necked portion fitting said longitudinal slot and a head adapted to pass through the enlarged end thereof, a shearing pin holding said pressure member to said igniter casing, a support for said cylindrical pressure member and means for adjusting said support so as'to leave space for movement of said pressure member shearing said shearing pin and releasing said'striking bolt to fire said mine 6. In an explosive mine, the combinatibn of a disk-shaped casing, an explosive charge contained'in said casing, a plurality of radially arranged igniter tubes within the exlosive in said casing, a striking bolt in each igniter tube, a spring for actuating eachstriking bolt, a pressure actuated retaining member arranged transversely adjacent the outer end of each ignitertube adapted in normal position to'retain each striking bolt and in another position to release same.

7 In an explosive mine, the combination of a disk-shaped caslng, an explosive charge cona disk-shaped casing, an explosive charge con tained in said casing, a plurality of igniter tubes arranged in star fashion in sald casing and opening towards the centre, a spring pressed striking bolt in each igniter tube, a

pressure member arranged transversely at the rear of each striking bolt and retaining said bolt in normal position, a shearing pin lightly holding each pressure member, a star-shaped rotatable plate adapted in one position to hold the pressure members in normal position against movement and in another position to release same, and a rotatable valve member arranged axially in said casing having passages interconnecting said igniter tubes and adapted to be rotated to close said igniter tubes.

9. In an explosive mine, the combination of a disk-shaped casing, an explosive charge contained in said casing, a plurality of igniter tubes arranged in star fashion in said casing and opening towards the centre, a spring pressed striking bolt in each igniter tube, a

-= pres-sure member arranged transversely at the rear of each striking bolt and retaining said bolt in normal position, a rotatable valve member arranged axially in said casing having passages interconnecting said igniter tubes and adapted to be rotated to close said i gniter tubes and a star-shaped rotatable plate secured on said valve member adapted in the closed position of the valve to enter slots in the pressure members and in the open position of the valve to leave said slots.

10. In an explosive mine, the combination of a disk-shaped casing, an explosive charge contained in said casing, a plurality of igniter tubes arranged in star fashion in said casing and opening towards the centre, a spring pressed striking bolt in each igniter tube, a pressure member arranged transversely at the rear of each striking bolt and retaining said bolt in normal position, a rotatable valve member arranged axially in said casing having passages interconnecting said igniter tubes and adapted to be rotated to close said igniter tubes and a detonator tube arranged radially between every two igniter tubes extending at one end through the casing and opening at the other end into passages of said rotatable valve member.

11. In an explosive mine, the combination of a two part disk casing, each part charged with explosive, a bayonet fastening for securin said casings together with a predetermlned clearance, a plurality of igniter tubes and detonator tubes alternately arranged in star fashion in one part casing, spring actuated striking bolt in each igniter tube, pressure actuated retaining members transversely positioned at the outer end of each igniter tube for normally holding the striking bolts, a rotatable valve member at the centre of the casing adapted in one position to interconnect said igniter and detonator tubes and in the other osition to close them from one another an a safety plate positioned'between the two casings secured on said rotatable valve member. dapted to hold the said retaining members rom movement in the closed position of said valve and to release said retaining members in the open-position of the valve.

12. In an explosive mine, the combination of a two art disk casing, each part -charged with exp osive, a bayonet fastening for securing said casings together with a predetermined clearance, a plurality of igniter tubes and detonator tubes alternately arranged in star fashion in one part casing, a spring actuated striking bolt in each igniter tube, pressure actuated retaining members transversely positioned at the outer end of each igniter tube for normally holding the striking bolts, a rotatable valve member at the centre of the casing adapted in one position to interconnect said igniter and detonator tubes and in the other position to close them from one another and a safety plate positioned between the two casin s secured on said rotatable valve member adapted to hold the said retaining members from' movement in the closed position of said valve and to release said retaining members in the open position of the valve, the two parts of said mine being adapted for use together as a contact 'm1ne or separately, one part as contact mine and the other as hand grenade or distant control mine.

In testimony whereof I have signed my name to this specification.

HANS GRUBER.

llO 

